McConnell called on Stevens to resign last week after the Alaska senator was convicted on seven federal felony counts. McConnell said there was “zero chance” Stevens wouldn’t be expelled from the Senate if he didn’t resign – but he also made it clear that Stevens would have a chance to appeal his conviction first.

Stevens, who has rebuffed calls to quit, claims he has “not been convicted yet” because he still has the right to appeal.

Of course, all the back-and-forth will be moot if Stevens loses his still-too-close-to-call reelection contest against Anchorage Mayor Mark Begich. As of Thursday night, a defiant Stevens led Begich by a few thousand votes, with thousands of absentee ballots yet to be counted.

State elections officials don’t expect an official result until later this month – possibly after Stevens has returned to the Senate for its “lame duck” session.

Under GOP rules, Stevens was stripped of ranking-member status on the Commerce Committee and the powerful Defense Appropriations subcommittee after he was indicted on charges that he failed to report $250,000 in gifts.

Senate Republicans could vote to eject Stevens from their caucus at any time — although there are as yet no plans to do so.

Expulsion from the Senate requires a two-thirds majority – 67 votes – to pass. If McConnell doesn’t press for Stevens’ expulsion during the November special session, DeMint plans to introduce a motion to expel in January, GOP staffers say.

“It takes only one senator to offer an expulsion motion,” said a Republican aide familiar with DeMint’s plans. “We deserve ridicule if we don’t follow through on our promises… This is a test of McConnell’s leadership.”

A McConnell spokesman declined to comment directly on DeMint’s challenge but e-mailed the statement the minority leader made in the immediate aftermath of Stevens’ trial: “If he is re-elected and the felony charge stands through the appeals process, there is zero chance that a senator with a felony conviction would not be expelled from the Senate.”

But a senior Democratic aide said the “ball was in McConnell’s court,” and Reid was waiting for McConnell’s cues on how and when to proceed.

Previous criminal cases involving senators have been routed through the ethics committee, which conducts investigations in private and, when appropriate, refers charges to the larger Senate.

But that can be a tortuous, time-consuming process. In the early 1980s, an ethics probe into bribery charges against New Jersey Democrat Harrison Williams dragged on for nearly a year before he resigned.

The chances of DeMint’s motion actually coming to a vote are remote - but it would put leadership in the awkward position of delaying Stevens’ day of reckoning.

Reid, who controls the chamber’s calendar, would have the option of fast-tracking an expulsion vote, delaying consideration for weeks, or, in the most likely scenario, referring it to the ethics committee, which is chaired by California Democrat Barbara Boxer.

There is also the possibility, according to one Republican aide, that DeMint could be stopped by a technicality requiring unanimous consent for the motion to be considered.

In that case, any member – including Stevens himself – could table the motion without a vote.